Blowing a fuse doesn't neccesarily mean that you have a short (though you may), just that you're drawing too much current. A "short circuit" happens when a circuit is grounded before current reaches its intended load (like a bulb or motor), such as when a wire's insulation rubs through and the wire touches metal (ground). Electricity takes the path of least resistance, so current goes to the new ground instead of to the load. This can cause a fuse to blow if the "new" circuit draws too much current. FYI, if a wire is cut all the way through or disconnected, thereby preventing the flow of current, that is referred to as an "open circuit".

Which fuse are you blowing? Blower motors are notorious for drawing too much current as they die, causing the fuse to blow.

__________________
1982 300D, black w/ palomino leather, 203K
2001 E320, champagne, 105K (Mom's)
1999 Dodge Dakota, squeaky & battered, 142K